Rectifiers

[Tony Allgood]

A little while ago I wrote about active rectifiers. Use the one in Horowitz
and Hill with a TL072 and BAT-42s and it works a treat. Fast and very little
breakthrough of the fundamental. With 1N4148s, the breakthrough is audible.
If you use a small trimmer (2k2) to divert the signal into either the summer
OR the rectifier op-amp the breakthrough can be minimised still further by
making the gain through each path identical. I used 100k resistors
throughout. Two in parallel for r/2.

Regards,

Tony Allgood, Cumbria, UK

e-mail: oakley at enterprise.net

Rack mounted Moog VCF module. Details to be found at...

http://aupe.phys.andrews.edu/diy_archive/schematics/effects/filter.html